The present invention relates to a wind power hybrid rotor, a wind power plant with a hybrid rotor, the use of a wind power hybrid rotor in a wind power plant and a method for converting wind energy into drive energy for performing work.
Rotors are used in wind power plants to be able to utilize wind energy to generate electrical energy. These rotors are set in rotation by the wind, thereby driving, e.g., a generator, i.e., the wind energy is at least partially converted into mechanical energy. Apart from the use for generating electrical energy, rotors are also used in particular for performing work, for example pumping or feeding work. Wind power plants are suitable, for example, for use in undeveloped or sparsely populated areas, for example, for decentralized energy supply. In addition, the use of wind power plants also gains increasing importance in connection with efforts concerning the utilization of regenerative energy sources.
There is a demand for a utilization of wind energy in a manner as efficient as possible.
This is achieved by a wind power hybrid rotor, a wind power plant, the use of a hybrid rotor in a wind power plant and by a method according to the present invention.
According to an exemplary embodiment of the invention, a wind power hybrid rotor is provided with a cross-flow rotor, a guide device and a Magnus rotor. The cross-flow rotor is supported so as to be rotatable about a rotational axis and has a plurality of axially extending rotor blades. The guide device has a housing segment partially enclosing the cross-flow rotor in the circumferential direction in such a manner that the cross-flow rotor can be driven by inflowing wind. The Magnus rotor is arranged within the cross-flow rotor, wherein the Magnus rotor axis extends in the direction of the rotational axis. The Magnus rotor has a closed lateral surface and is rotatably drivable by a drive device about the Magnus rotor axis.
By combining a cross-flow rotor with a Magnus rotor, a more efficient utilization of the wind power is made available compared to only a corresponding cross-flow rotor.
According to one aspect of the invention, the Magnus rotor is a rotationally symmetric hollow body which, by means of the Magnus effect, effects a deflection of an air flow.
According to this invention, the cross-flow rotor causes a circulating flow. This circulating flow is a rotational air flow which, at the same time, is superimposed with a translational air flow. The latter, in turn, is the cross inflow caused by the incoming wind flow. This combination flow causes the Magnus effect on a geometrical body subjected to the combination flow. Therefore, this body is designated as Magnus body.
In case of the combination flow, the rotational air flow can also be generated or facilitated by rotatingly driving the Magnus body. The rotation of the Magnus body or the Magnus rotor results in a stronger development of the Magnus effect and thus also in a stronger deflection of the air flow according to the invention.
The determining factor for the Magnus effect is the relative movement between the surface of the Magnus body and the combination flow with the mentioned cross deflection or cross flow and the circulating flow.
It should expressly be noted that due to the rotating cross-flow rotor in combination with the wind-air flow, e.g., a stationary Magnus body, for example, a stationary cylinder, can already cause a Magnus effect.
For example, the Magnus rotor is formed with a circular cross-section, i.e., with a diameter which remains constant along the rotational axis, thus in the form of a cylinder in a geometrical sense.
For example, the Magnus rotor can also be formed with a circular diameter that changes uniformly along the rotational axis, i.e., as a truncated cone.
For example, the Magnus rotor can have a diameter that increases and decreases again in a parabolic manner. For example, the Magnus rotor is a ball.
For example, the Magnus rotor can also be composed of different truncated cone segments and/or cylinder segments.
According to a further aspect of the invention, the Magnus rotor can be driven in the rotational direction of the cross-flow rotor.
According to a further aspect, the Magnus rotor can be driven counter to the rotational direction of the cross-flow rotor.
According to a further aspect of the invention, the rotational axis and the Magnus rotor axis are arranged transverse to the inflow direction of the wind.
According to a further aspect of the invention, the Magnus rotor axis runs parallel to the rotational axis of the cross-flow rotor.
According to a further aspect of the invention, the Magnus rotor is arranged concentrically with the cross-flow rotor.
According to an alternative aspect of the invention, the Magnus rotor axis is formed inclined with respect to the rotational axis of the cross-flow rotor, wherein the Magnus rotor axis spans a plane with the rotational axis. According to a further aspect of the invention, the Magnus rotor axis and the rotational axis of the cross-flow rotor can also be arranged inclined with respect to each other in such a manner that they lie in different planes, i.e., not in a common plane.
According to a further aspect of the invention, the housing segment shields the cross-flow rotor with respect to the rotational axis of the cross-flow rotor on the windward side on one side of the rotational axis.
According to a further aspect of the invention, the windward side is divided by a line into two segments, wherein the line extends in the direction of inflow and intersects the rotational axis.
According to a further aspect of the invention, the housing segment has a circular arc shape on the side facing toward the cross-flow rotor.
According to a further aspect of the invention, the housing segment is formed with the same cross-sectional shape over the entire length of the Magnus rotor.
According to an alternative aspect of the invention, the housing segment has different cross-sectional shapes over the length of the Magnus rotor. Accordingly, it is possible, for example, to provide additional steering effects with respect to the inflow, e.g., depending on the respective position with regard to the inflow.
According to a further exemplary embodiment of the invention, during rotation, the Magnus rotor effects on its lee side a deflection of the air flow with respect to the direction of the inflow.
According to a further aspect of the invention, the deflection takes place at or above a circumferential speed of the Magnus rotor which is preferably higher than the inflow speed of the wind power hybrid rotor.
According to a further exemplary embodiment of the invention, the deflection takes place in such a manner that air flow flowing through the cross-flow rotor acts on the rotor blades in an expanded circular arc and drives said rotor blades.
According to a further aspect of the invention, the deflection causes the air flow flowing through the cross-flow to act on the rotor blades in an additional circular arc segment of up to 90°.
According to a further aspect of the invention, in the axial direction, the rotor blades extend parallel to the rotational axis, i.e., they have a constant distance from the rotational axis.
According to an alternative aspect of the invention, in the axial direction, the rotor blades extend inclined to the rotational axis, wherein the rotor blades have an increasing or decreasing distance from the rotational axis, i.e., the rotor blades extend in each case in one plane with the rotational axis, but inclined to the rotational axis.
According to a further aspect of the invention, the cross-flow rotor has a rotating rotor axle and the rotor blades are retained on a support structure which also rotates and is fastened to the rotating rotor axle.
According to a further aspect of the invention, the rotor blades are configured to be stationary with respect to the tangential angular position.
According to a further exemplary embodiment of the invention, the rotor blades have a cross-section with a curved shape comprising a concave and a convex side, wherein the concave side faces toward the Magnus rotor.
According to a further aspect of the invention, the cross-section of the rotor blades have an angle of 15° to 70° with respect to the radial direction. For example, the cross-section of the rotor blades have an angle of 30° with respect to the radial direction. The term radial direction refers to a connection line between the rotor axis and the center of the cross-section of the rotor blade, and the direction of the cross-section, in case of a curved cross-sectional shape, refers to the tangential direction.
According to a further aspect of the invention, at least two, preferably 16 rotor blades are provided.
According to a further aspect of the invention, a distance is provided in the radial direction between the lateral surface of the Magnus rotor and the rotating rotor blades, wherein said distance depends on the diameter of the Magnus rotor.
For example, the diameter of the Magnus rotor is equal to or double the distance between the lateral surface and the rotor blades.
According to a further example, the ratio of diameter of the Magnus rotor and distance from the rotor blades is 2:1.
According to one aspect of the invention, the profile depth and the curvature of the rotor blades can be selected as desired, wherein these two parameters are in a relationship to each other with respect to the operational effect. In case of a very small profile depth and a correspondingly small distance, the curvature of the individual rotor blade is less significant. In addition, the diameter of the cross-flow rotor can be determined. The number of rotor blades in turn is associated with the diameter of the cross-flow rotor and the profile depth. Once these variables are determined, the inside diameter of the cross-flow rotor is also known, thus the distance of the rotor blades from the center. The diameter of the Magnus body, e.g. of a cylinder, then results from the above-mentioned ratio of distance between the rotor blades and the lateral surface of the Magnus body to the diameter of the Magnus body.
According to a further aspect of the invention, a distance is provided in the radial direction between the lateral surface of the Magnus rotor and the rotating blades, wherein said distance is one to two times the profile depth of a rotor blade, wherein the profile depth is measured independent of the angular position.
According to a further aspect of the invention, the rotor blades of the cross-flow rotor are arranged along a circular line about the rotational axis, wherein the circle has a diameter which is approximately five to eight times the profile depth of a rotor blade.
According to a further aspect of the invention, a circumferential distance of the rotor blades from each other is provided which is at least the profile depth of the rotor blades.
According to a further aspect of the invention, the axially extending rotor blades are divided into rotor blade segments and are formed differently over the entire length.
According to a further aspect of the invention, the Magnus rotor is divided into Magnus rotor segments which can be driven with a different speed.
According to a further aspect of the invention, the Magnus rotor has in the region of its ends in each case one end disk protruding beyond the circumferential surface of the Magnus rotor.
According to a further aspect of the invention, the Magnus rotor has a plurality of disks arranged between the two end disks. The disks have a greater diameter than the adjacent lateral surface segments of the Magnus rotor.
According to a further aspect of the invention, the cross-flow rotor has a repeller which can be driven by the wind.
According to a further exemplary embodiment of the invention, the Magnus rotor is driven with a circumferential speed which is approximately one to four times the inflow speed of the wind power hybrid rotor.
According to a further aspect of the invention, the cross-flow rotor has a circumferential speed which is approximately 50% of the inflow speed of the wind power hybrid rotor.
According to a further aspect of the invention, the ratio of rotation between the cross-flow rotor and the Magnus rotor is approximately 1:2 to 1:8.
According to a further aspect of the invention, the ratio of inflow speed of the wind power hybrid rotor/circumferential speed of the cross-flow rotor/circumferential speed of the Magnus rotor is approximately 1/1/1-4.
According to a further aspect of the invention, a transmission gear is provided between the cross-flow rotor and the Magnus rotor.
According to a further aspect of the invention, the transmission ratio of the transmission gear is changeable, for example in steps or stepless, e.g., depending on the wind force.
According to a further aspect of the invention, the wind force drives the Magnus rotor.
According a further exemplary embodiment of the invention, the cross-flow rotor drives the Magnus rotor.
This can take place, for example, via the transmission gear.
According to a further aspect of the invention, the cross-flow rotor provides energy for driving the Magnus rotor, e.g., by means of an electrical drive solution of the Magnus rotor.
According to a further aspect of the invention, the Magnus rotor, for starting up the wind power hybrid rotor, is electrically driven so as to enable a start up even in conditions of low wind.
According to a further aspect of the invention, the housing segment has a displacement mechanism and is configured in a pivotable manner at least with respect to the rotational axis of the cross-flow rotor.
According to a further exemplary embodiment of the invention, the displacement mechanism can be set depending on an inflow direction in such a manner that the housing segment shields the cross-flow rotor with respect to the rotational axis of the cross-flow rotor on the windward side on one side of the rotational axis.
According to a further aspect of the invention, the displacement mechanism has a wind sensor.
According to a further aspect of the invention, the wind sensor is a wind vane which is coupled to the displacement mechanism.
Also, according to the invention, a wind power plant comprises a rotor unit for converting wind movement into a rotational movement, a work device for converting the kinetic energy of the rotational movement into work to be performed, and a gear device for coupling the rotor unit to the drive device for transmitting the rotational movement to the work device. The rotor unit has at least one wind power hybrid rotor according to any one of the preceding exemplary embodiments or aspects of the invention.
According to a further exemplary embodiment of the invention, the work device is a current generator for generating electrical energy.
According to a further exemplary embodiment of the invention, the work device is a pump device, for example, for supplying drinking water or for pumping water for irrigation plants or also for drainage purposes, i.e., draining by pumping.
According to a further aspect of the invention, the work device is, for example, a mill unit for carrying out mill work, for example for driving milling processes, sawing processes, grinding processes etc.
According to a further aspect of the invention, a combination of the mentioned work devices is provided.
According to a further aspect of the invention, the rotor axis is arranged vertically, i.e., the rotational axis of the cross-flow rotor and also the Magnus rotor axis extend vertically.
According to an alternative aspect of the invention, the rotor axis is arranged horizontally.
According to a further aspect of the invention, the wind power hybrid rotor can be aligned with an inflow direction, for example, particularly if the rotor axis is arranged horizontally.
According to a further aspect of the invention, the wind power plant has a support construction on which the rotor unit, the gear device and the work device, for example, a generator, are retained.
According to a further aspect of the invention, the support construction is anchored in a foundation in the ground.
According to an alternative aspect of the invention, the support construction is anchored on a building structure, for example on a building such as, for example, a house or a bridge structure.
According to the invention, also, the use of a wind power hybrid rotor according to any one of the preceding exemplary embodiments and aspects of the invention is provided.
According to the invention, a method for converting wind energy into drive energy for performing work comprises the following steps which can also be designated as processes or sequences and take place at the same time:
a) Rotating a cross-flow rotor that is supported so as to be rotatable about a rotational axis and has a plurality of axially extending rotor blades; wherein a guide device is provided which has a housing segment which partially encloses the cross-flow rotor in the circumferential direction in such a manner that the cross-flow rotor is driven by inflowing wind.
b) Rotating a Magnus rotor arranged within the cross-flow rotor and the Magnus rotor axis of which extends in the direction of the rotational axis; wherein the Magnus rotor has a closed lateral surface and is driven by a drive device about the Magnus rotor axis.
c) Driving a work device by the cross-flow rotor.
The Magnus rotor deflects in step b) on its lee side with respect to the inflow direction in such a manner that the air flow flowing through the cross-flow rotor in step a) acts on the rotor blades in an expanded circular arc.
According to a further aspect of the invention, the Magnus rotor in step b) deflects the air flow by rotating at a circumferential speed which is higher than the inflow speed of the wind power hybrid rotor.
The direction of rotation of the Magnus rotor preferably takes place in the rotational direction of the cross-flow rotor, for example with a 0- to 4-fold rotational speed with respect to the speed of the inflowing air, i.e., with respect to the local wind speed.
According to a further aspect of the invention the Magnus rotor can rotate counter to the rotational direction of the cross-flow rotor, e.g., depending on the configuration of the cross-flow rotor.
For example, rotating of the Magnus rotor counter to the rotational direction of the cross-flow rotor and thus rotating of the two rotors in opposite directions can be provided, e.g., to enable braking in case of excessively strong winds.
According to a further aspect of the invention, measures for changing the surface roughness are provided, e.g., the latter is increased by a special surface structure. Thereby, depending on the expected wind speeds, the laminar flow or boundary layer flow can be influenced.
For example, the surface of the Magnus rotor can have a plurality of deepenings, e.g., a plurality of dents or dints.
For example, the surface can also have a plurality of elevations projecting from the surface, e.g., linear or punctiform elevations.
Thus, due to the deflection, a better utilization of the wind energy occurs, i.e., the rotor has overall a greater efficiency. Due to the Magnus effect, this efficiency is given despite the energy required for driving the Magnus rotor.
According to a further aspect of the invention, the work to be performed is the generation of electrical current.
According to a further aspect of the invention, the work to be performed is pumping water.
According to a further aspect of the invention, the work to be performed is mill work.
According to a further aspect of the invention, the work device is a current generator, and between the cross-flow rotor and the current generator, a gear device is provided by means of which the movement is transferred from the rotating cross-flow rotor to the work device.
According to a further aspect of the invention, the cross-flow rotor is shielded in step a) by the housing segment with respect to the rotational axis of the cross-flow rotor on the windward side on one side of the rotational axis.
According to a further aspect of the invention, the Magnus rotor is driven in step b) by the cross-flow rotor, for example, by direct coupling via a transmission gear or via an electrical drive of the Magnus rotor, wherein the electrical energy is generated by a generator which is driven by the cross-flow rotor.
It should be noted that the features of the exemplary embodiments and aspects of the devices also apply to embodiments of the method and to the use of the device and vice versa. Moreover, even those features for which this is not explicitly mentioned can be freely combined with each other.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.